Pulp is a generic term for a wide range of technically distinct products resulting from complex manufacturing processes that involve the chemical and/or mechanical treatment of various types of plant material. Wood currently provides the basis for approximately 90% of global pulp production; the remaining 10% begins as straw, bamboo, bagasse, kenaf, flax, hemp, cotton, and the like. Pulp is used predominantly as a major component in the manufacture of paper and paperboard. Smaller quantities of pulp find their way into a diversity of products—rayon, photographic films, cellophane and explosives.
The highest grade of pulp is chemical-grade or dissolving-grade pulp. Dissolving pulp is used in the manufacture of value-added products such as:                viscose fiber (rayon) or film, made by dissolving pulp in alkaline carbon disulfide (xanthation) thus forming the xanthate salt as an intermediate product, and forcing the solution through orifices into an acid bath.        cellulose derivatives such as cellulose acetate, ethyl cellulose, cellulose nitrate (nitrocellulose, guncotton), and carboxymethylcellulose (CMC).        
Dissolving pulp manufacture usually utilizes kraft or sulfite pulping of wood (both softwoods and hardwoods), or soda pulping of cotton linters. When pulping wood for dissolving pulp, the bleached yield is only 32-36% so as to obtain purer pulp. The cellulose content is commonly 88-93% (for commodity grade viscose), but may be as high as 98% for more demanding end-uses (eg: tire cord). The contents of extractives, lignin, iron and ash are also low. Viscosity (ie: DP) is another important property, with the actual level depending on the end-use of the pulp. For commodity grade viscose, the viscosity may be about 350 to about 550 ml/g. High grade dissolving pulp may exceed 600 ml/g.
To create dissolving pulp, conventional kraft pulping is modified to include a prehydrolysis stage, before the main cook, where the hemicellulose is hydrolyzed and removed. Dilute acid or alkali, or just direct steam, is used in this prehydrolysis stage. This additional stage approximately doubles total cooking time, relative to a normal kraft cook. A cold alkali extraction stage in the bleaching sequence further removes the non-cellulose components.
Acid sulfite pulping is carried out at a high temperature and low pH to achieve the desired hemicellulose degradation. Bleaching includes a hot alkali extraction stage to further remove the non-cellulose components.
Some studies have indicated that dissolving pulp may be obtainable from either bleached hardwood kraft market pulp or high quality wood pulp rich in hardwood fiber. The sequence included two cold alkali extraction stages with xylanase treatment in between. [Jackson, L. S. et al. Production of dissolving pulp from recovered paper using enzymes. TAPPI Journal, March 1998].
These prior art methods of producing dissolving pulp consume large amounts of chemicals and energy, and require complex black liquor recycling processes. A separate bleaching step is required after alkaline degumming.
Therefore, there is a need in the art for methods of producing degummed pulp suitable for producing dissolving pulp which mitigates the disadvantages of the prior art.